With the dramatic proliferation of mobile phones in recent years, phone etiquette has become an important issue. In public places such as trains and buses and working places such as working rooms and meeting rooms, it is a common practice for the user of a mobile terminal to set it for an etiquette mode where it becomes silent and vibrates when it is receiving an incoming call. Of course, if the user carries the mobile terminal placed in a pocket of his or her clothing, no problem would occur. However, if the user has placed it on a desk or the like, it would vibrate on the desk or the like and create an unpleasant, rattle like sound. Next, with reference to the accompanying drawings, this problem will be described in detail.
FIG. 1 is a block diagram exemplifying the structure of a mobile terminal according to related art. FIG. 2 shows schematic diagrams describing the operation of a vibrator of a mobile terminal shown in FIG. 1.
As shown in FIG. 1, mobile terminal 90 has eccentric member 84; motor 83 that drives eccentric member 84; motor control circuit 82 that drives motor 83; and CPU (Central Processing Unit) 81 that controls motor control circuit 82. FIG. 2(a) is a perspective view showing appearance of mobile terminal 90 shown in FIG. 1. Mobile terminal 90 is a foldable mobile phone composed of lid section 91 and body section 92. FIG. 2(a) shows that lid section 91 is in the open state. Assuming that body section 92 formed in a rectangular parallelepiped shape has been placed horizontal on a desk in the state shown in FIG. 2(a), in which the shorter side direction of body section 92 is the X axis direction, and the longer side direction of body section 92 is the Y axis direction, the operation surface of body section 92 becomes perpendicular to the Z axis direction.
FIG. 2(b) is a schematic diagram showing substrate 95 provided in body section 92 of mobile terminal 90 that has been placed on a desk in the state shown in FIG. 2(a). As shown in FIG. 2(b), motor 83 is mounted on substrate 95 in parallel with the longer side of body section 92 of mobile terminal 90. Eccentric member 84 is mounted on the spindle of motor 83. The direction of the spindle of motor 83 matches the Y axis. If mobile terminal 90 that has been set for the etiquette mode is receiving an incoming call, CPU 81 transmits a control signal to motor control circuit 82 such that it drives motor 83. When motor control circuit 82 receives the control signal from CPU 81, motor control circuit 82 drives motor 83. When motor 83 rotates eccentric member 84, mobile terminal 90 generates vibrations and thereby the user knows that mobile terminal 90 is receiving an incoming call.
At this point, since eccentric member 84 rotates about an axis in parallel with the Y axis direction as shown in FIG. 2, the vibration direction becomes parallel to the XZ plane. If the user carries mobile terminal 90 placed in a pocket of his or her clothing, since the XZ plane of mobile terminal 90 becomes perpendicular to the user's skin, vibrations of mobile terminal 90 are easily transferred to the user's body. In contrast, if the user has placed mobile terminal 92 on a desk or the like, since the XZ plane of mobile terminal 90 becomes perpendicular to the surface of the desk, mobile terminal 92 vibrates and creates an unpleasant rattle-like sound.
Patent Literature 1 discloses a technique according to which a user is notified of an incoming call through a visual means whose goal is to solve the problem in which, if the mobile terminal that is placed on a desk receives an incoming call, the mobile terminal will vibrate and disturb the surrounding people due to the unpleasant sound that is generated.